Hammering a nail into wood, plaster, concrete, drywall or plastic, herein a substrate, requires that the nail be positioned properly both with respect to the substrate and with respect to the hammer, herein a driver. Nail guiding and driving tools (hereinafter “nail guides”) that position a nail with respect to a substrate are known. Among those suggested through the years are the tools disclosed in U.S. patent applications Ser. No. 952,571 to Lamb, U.S. Pat. No. 2,199,833 to Fleischman and U.S. Pat. No. 2,896,209 to Hilti. The Hilti patent in particular discloses a driving tool for driving studs, nails or fasteners (hereinafter referred to all as “nails”), comprising a tubular member adapted to be gripped in the hand, within which is guided a ram (or piston) actuated along a straight line by mechanical blows, e.g. from a hammer. The tool includes a flange arranged to rest against the material into which the nail is to be driven, and which prevents the tool from tilting. The exact alignment of the nail in the direction of penetration is assured by two guiding elements (rockable arms 62) between which the nail extends during the driving operation, and which are as remote from each other at the beginning of the driving operation as possible. As in the present invention, the tool in U.S. Pat. No. 2,896,209 accepts nails with heads.
Commercial nail-guiding and driving tools are also known, the most relevant to the present invention being a tool that we will call the “Hilti tool”. In contrast with the device disclosed in U.S. Pat. No. 2,896,209, the Hilti tool lacks the mentioned two guiding elements, and works only with headless nails. The holding and exact alignment of the nail in the direction of penetration is assured by a longitudinal (parallel to the driving axis) concentric hole drilled into the end of the piston. The headless nail is inserted into the hole, and driven into a substrate by blows imparted to the other end of the piston.
A main disadvantage of the tool in U.S. Pat. No. 2,896,209 is the rather complicated mechanism, which includes non-fixed guiding elements. On the other hand, a main disadvantage of the commercial Hilti tool is the fact that it works only with headless nails of a given diameter. Other nail guides, disclosed for example in U.S. Pat. Nos. 952,571 and 2,199,833 require other additional means to hold the nail as it is being driven-in. Yet other patents, such as U.S. Pat. No. 5,529,234, use magnetized materials to hold the nail, therefore being both complicated and working only on magnetic nails.
There is thus a widely recognized need for, and it would be highly advantageous to have, a simple and inexpensive handheld nail guide tool that assists in the proper holding, positioning and guiding of a regular nail (with a head) without resorting to movable guiding elements, magnetic means, or any other disadvantageous feature existing in prior art guide tools.